JP5089507B2 - Environmental improvement material, environmental restoration material in coastal area, artificial tidal flat, artificial tidal flat creation method, soil layer improvement material, crop cultivation soil, crop cultivation soil creation method, and crop production method - Google Patents

Description

  The present invention relates to an environmental improvement material, and in particular, an environmental restoration material, an artificial tidal flat, and an artificial tidal flat creation method in a coastal area, and a soil layer improvement material, a crop cultivation soil, a crop cultivation soil creation method, and a crop production Regarding the method.

  In recent years, various efforts have been actively made to artificially restore the natural environment, which has been destroyed by humans with the development of industry, to the original environment. As part of such efforts, efforts to restore nature on the seaside are now active. As for the natural regeneration of the seaside, in addition to regeneration techniques such as coral reefs and seaweed beds, techniques related to the creation of tidal flats are drawing attention.

  Patent Document 1 discloses a mixed soil for artificial tidal flats used for constructing artificial tidal flats. The mixed soil for artificial tidal flats described in Patent Document 1 is obtained by mixing a small amount of silt / viscous soil obtained by seabed dredging with sandy soil obtained by seabed dredging than the above sandy soil. . According to the mixed soil for artificial tidal flats described in Patent Document 1, by using the dredged soil of the port close to the environment of the creation site, for example, compared to the case of using sand and sand brought in from the external environment such as mountains, the biological environment The ecosystem is not destroyed. Moreover, since sandy soil and silt / viscous soil are mixed, the water permeability and the ability to purify seawater by the synergistic effect of the amount of existing bacteria are excellent.

  Further, Patent Document 2 discloses an artificial tidal flat constructed using a construction material in which an organic substance-mixed material and a sandy material are mixed, and a construction method therefor. In addition to dredged soil, organic matter-contaminated materials include unnecessary materials that are discharged during aquaculture and food manufacturing processes. In addition to sandy soil, mountain sand and sea sand are used as sandy materials. Since the artificial tidal flat described in Patent Document 2 contains an appropriate amount of organic matter, it is a favorable environment for benthic organisms that inhabit the tidal flat.

Patent Document 3 discloses a tidal flat composed of dredged sand and steel slag, and a shallow water environment restoration material. If the tidal flat and shallow water environment restoration material described in Patent Document 3 is used, it is not necessary to adjust the particle size necessary for ensuring water quality purification when only dredged soil is used. Further, it is possible to prevent an increase in pH in the peripheral region that occurs when only blast furnace granulated slag is used.
JP 2001-295240 A (released on October 26, 2001) JP 2003-268745 A (published on September 25, 2003) JP 2005-133309 A (published May 26, 2005)

  In the above prior art, sea sand is mainly used as a material for constructing artificial tidal flats. Sea sand is collected from the seabed such as harbors. As fossil resources, sea sand, like oil and coal, is neither regenerated nor replenished, and once collected, it is lost forever. Moreover, there is a problem that coastal erosion occurs in the surrounding area by collecting sea sand.

  In addition, the sea sand at the depth of sunlight has the function of water purification, as opposed to mud, a substance associated with pollution. Water purification by sea sand does not mean that the sand itself has a function of purifying water, but organisms living there decompose organic substances that cause pollution. Therefore, collecting a large amount of sea sand that can be said to be a sea cleaner leads to deterioration of the water quality environment in the sea. For this reason, the problem of having a bad influence on surrounding fishery environment and damaging fishery production also arises.

  Under these circumstances, sea sand collection is currently prohibited in the Seto Inland Sea except for the purpose of maintaining the route. In addition, the Seto Inland Sea is the number one in Japan for the purpose of maintaining the route. In addition, dredging aimed at maintaining the route is also carried out in Tokyo Bay, but the amount of dredging is small due to the small number of routes. Furthermore, in the case of Ise Bay, the water depth is originally deep and there is not much need for dredging in the first place. Moreover, dredging aimed at maintaining the route is conducted under the control of the Ministry of Land, Infrastructure, Transport and Tourism, but the sediment obtained from dredging aimed at maintaining the route is centrally managed by the country (the jurisdiction of the Ministry of Land, Infrastructure, Transport and Tourism). The destination is determined. Therefore, dredged sand for the purpose of maintaining the channel is not generally distributed.

  Therefore, at present, there is a problem that it is becoming difficult to obtain dredged sand as a material for constructing artificial tidal flats.

Although salmon sludge is available, there are too many organic substances, so it cannot be used alone as a material for constructing artificial tidal flats. The sea sand obtained by dredging is almost the same as the particle size of concrete aggregate, and the amount of sea sand collected nationwide is about 30 million m ³ per year, of which 23 million tons are for raw concrete aggregate. It has become. In addition, sea sand consumers and suppliers are unevenly distributed in western Japan, with the most along the Seto Inland Coast. In western Japan, it relies on sea sand, while in eastern Japan, mountain sand is the mainstream. In this way, by collecting a large amount of sea sand as a concrete aggregate, for example, sand having a particle size substantially the same as the standard particle size of concrete aggregate (sand having a particle size of 0.5 to 2.0 mm) is a resting place. Ikanago has lost its home.

  Patent Document 2 describes the use of mountain sand as sandy material, but land sand has low physical wear and has an adverse effect on submarine behavior such as bivalve larvae. Therefore, it is not suitable as a growth environment for juvenile shellfish.

  Patent Document 3 describes the use of steel slag as a tidal flat restoration material, but steel slag (that is, blast furnace slag) has a risk of metal elution, so an actual use example is rare. The slag generated from the power plant is the same as the steel slag.

  A method of using cultured oyster shells as an artificial tidal flat is also proposed. Cultured oyster shells are porous and suitable for bacterial propagation. However, when used as a material for constructing artificial tidal flats, pulverization is required, and costs are required for processing and equipment. Moreover, since the specific gravity is small and washed away, it cannot be used alone.

  In addition, it is possible to use crushed sand as a material for constructing artificial tidal flats. Crushed sand is artificial sand made by finely pulverizing rocks, and is distributed as a mixture for adjusting the particle size and salt concentration of raw corn aggregate mainly composed of sea sand. However, crushed sand is artificially processed sand and is costly, so it is suitable for use for purposes such as particle size adjustment.

  It is also possible to use dam sediment sand as a material for constructing artificial tidal flats. However, although dam sedimentary sand comes out in large quantities, it is sludge-like and contaminated because it contains dead leaves, dead trees, etc. derived from land plants, so secondary treatment (drying and / or washing) ) Is required, and costs are required for facilities, work, and transportation.

  It is also possible to use river sand as an artificial tidal flat material. River sand is sand that is collected especially in the estuary and has good quality. Therefore, while it is necessary to mix organic matter with the sand collected in the revetment area, river sand collected in the estuary area can be used without mixing organic substances (such as sludge). However, river sand in the estuary has been collected so far, so it is almost impossible to collect it at present and is very expensive, so it is difficult to use it as a material for constructing artificial tidal flats.

  By the way, sea sand is used not only for the construction of artificial tidal flats, that is, as an environmental restoration material, but also for the cultivation of agricultural crops. And even when sea sand is used for these purposes, as in the case where sea sand is used for the artificial tidal flat described above, by collecting too much sea sand, the underwater environment around the area where sea sand was collected There is a problem that it will adversely affect

  Therefore, the appearance of new materials that can be used in various fields in place of sea sand is awaited.

  By the way, when producing iodine, brine is pumped from the groundwater layer. The brine contains sand and when iodine is extracted from the brine, the sand is removed together with waste. Currently, the sand that has been removed by sedimentation is disposed of, which increases the costs required to secure and maintain the disposal site, as well as to transport and reclaim sand. There is a problem that resources are not effectively utilized.

  The present invention has been made in view of the above problems, and its purpose is to make effective use of irrigation sand contained in irrigation water, environmental improvement materials, environmental restoration materials in coastal areas, artificial tidal flats, artificial tidal flat formations. It is an object of the present invention to provide a method, a soil layer improving material, a crop cultivation soil, a crop cultivation soil creation method, and a crop production method.

  The material for improving environment according to the present invention is characterized by containing brine sand contained in brine produced from a groundwater layer.

  According to said structure, the material for environmental improvement which concerns on this invention contains the brine sand contained in brine. Brine is groundwater that contains a large amount of salt, and is produced, for example, from an old stratum that dissolves natural gas. And the irrigation sand can be taken out from the irrigation water pumped up from the groundwater layer. Note that the irrigation sand contained in the irrigation water is not limited to sand in the state of being contained in the pumped irrigation water. That is, it includes those that have already been removed from the brine by being precipitated and discarded, and are not particularly limited.

  Since brackish sand is exposed to water having almost the same chemical composition as seawater, it has salinity and features similar to sea sand. In addition, the sand surface is worn by the erosion action for many years, and it has a granular shape suitable for the living environment of benthic organisms. Furthermore, in many cases, the brine sand contained in the brine contains various nutrients such as iodine and various minerals.

  Therefore, according to the environmental improvement material containing irrigation sand, for example, when mixed with soil for cultivating a crop in an arable land such as a field, the growth of the crop can be promoted. That is, the environment of soil such as a field can be improved. For example, if it is used as a material for artificially constructing tidal flats and seaweed beds in coastal areas, a sediment environment suitable for inhabiting benthic organisms can be created. That is, the coastal environment can be improved. Therefore, if the environmental improvement material which concerns on this invention is used, it will become possible to use a brine sand effectively.

  Moreover, the environmental restoration material in the coastal area which concerns on this invention consists of the said material for environmental improvement. Moreover, the artificial tidal flat according to the present invention is characterized by being constructed using an environmental restoration material in the coastal area. The artificial tidal flat creation method according to the present invention is characterized in that the artificial tidal flat is created using the environmental restoration material in the coastal area.

  The brackish sand is suitable for the habitat environment of benthic organisms and can activate the habitat of benthic organisms. Therefore, the water quality is purified by benthic organisms, and the coastal environment can be restored.

  The soil layer improving material according to the present invention is characterized by comprising the above-mentioned environmental improving material. Moreover, the crop cultivation soil which concerns on this invention is characterized by including the said soil-layer improvement material. Moreover, the crop cultivation soil preparation method according to the present invention is characterized in that the soil layer improving material is mixed. The crop production method according to the present invention is characterized in that the soil layer improving material is used as a soil for cultivation of crops.

  Because brackish sand is exposed to water with almost the same chemical composition as seawater, its composition is close to that of sea sand, and it often contains iodine and various minerals. Can be promoted. Therefore, according to the soil layer improving material according to the present invention, the air permeability and drainage of the cultivated land whose soil quality has deteriorated due to continuous cropping can be recovered, and more fertile soil can be obtained, and the environment can be restored.

  The material for improving environment according to the present invention is characterized by containing brine sand contained in brine produced from a groundwater layer. The brackish sand is suitable for the habitat environment of benthic organisms, and the biological activity is thriving, so the water quality can be purified by benthic organisms. In addition, brackish sand is exposed to water with almost the same chemical composition as seawater, so the composition is close to that of sea sand, and often contains iodine and various minerals. Since the cultivation can be promoted, the aeration and drainage of the cultivated land whose soil quality has deteriorated due to continuous cropping can be recovered, and the soil can be made more fertile. Therefore, according to the environment improving material according to the present invention, it is possible to improve the environment such as the coastal environment and the field soil, and to effectively use the irrigated sand.

[Artificial tidal flat]
The present invention is a technique relating to the creation of artificial tidal flats and the like for the purpose of restoring the biological habitat environment in coastal areas. The tidal flat environment is rich in organic mud and rich in nutrients. Air is mixed and absorbed by tidal currents and waves. Therefore, the tidal flat becomes an aerobic environment rich in dissolved oxygen. In such an aerobic environment, bacteria multiply while decomposing organic mud and purifying the underwater environment. The grown bacteria and microalgae are eaten by benthic organisms (for example, crabs, shrimps, shellfish, sea cucumbers, sea bream, etc.), and these benthic organisms feed on fish and birds, and are higher in the nutritional stage. The food chain circulates. In addition, nutrient salts decomposed by bacteria are absorbed by microalgae and proliferate, creating an excellent environment for fry and feeding grounds.

  Also, in the tidal flats, the function of benthic organisms is important. For example, bivalves act as a water purification by feeding the suspension with filtered water. The amount of filtered water by this bivalve is extremely large, which is very useful for water quality conservation. Therefore, as a countermeasure against red tide and blue tide, a bivalve breeding ground has been established. Examples of bivalves include clams, clams, swordfish, crabs, and scallops.

  In this way, the tidal flat is clean and rich in oxygen, and is a valuable place that connects the land and the sea in an ecologically continuous manner.

  However, since the middle of the 20th century, along with high economic growth, the development of coastal beaches with excellent conditions for living and logistics has been promoted, and tidal flats that are technically and economically easy to develop have been reclaimed. This hinders the development of shallow fields, the seabed becomes sludge, and benthic organisms that have sand as a bed cannot live in the mud. As a result, benthic organisms that previously lived in tidal flats will disappear and the food chain will be broken.

  Under these circumstances, with the disappearance of the tidal flat environment, there is an increasing interest in creating an artificial tidal flat and regenerating the tidal flat environment as described above.

  Moreover, it is preferable that the sand used for construction of an artificial tidal flat has a high degree of physical wear. For example, benthic larvae are difficult to grow on sand with low physical wear, such as earth and sand mined from mountains, and sand with the surface of sand particles is suitable for inhabiting benthic organisms. is there.

  The inventors can reduce the dependence on sea sand and regenerate an underwater environment suitable for benthic habitat even when constructing artificial tidal flats by using an environmental improvement material containing brine sand. I found. And if many benthic organisms inhabit, water quality will be purified by these benthic organisms. That is, the environment in the coastal area can be restored by using the environment improving material according to the present invention.

  In the present embodiment, an artificial tidal flat will be described as a specific example of using the environmental improvement material according to the present invention as an environmental restoration material in a coastal area. However, in addition to the artificial tidal flat, it is used for, for example, the construction of a clam farm. It can also be used for algae formation, dredging formation, sand cover, etc., and is not particularly limited.

  An embodiment of the present invention will be described below with reference to FIG.

  FIG. 1 shows an artificial tidal flat 2 according to the present invention. The artificial tidal flat 2 is constructed using an artificial tidal flat construction material 1 (environmental improvement material, environmental restoration material) mixed with brine sand contained in the brine produced from the groundwater layer. The present invention is characterized in that irrigation sand contained in the irrigation water produced from the groundwater layer is used in the construction of the artificial tidal flat.

  In the present embodiment, the artificial tidal flat construction material 1 includes crushed material of shells such as scallops and oysters, in addition to brine sand. However, the artificial tidal flat construction material 1 may be configured to include inorganic materials other than crushed shells or sludge, and is not particularly limited.

  Moreover, the conventional landfill technology can be used as the construction technology for constructing the artificial tidal flat. In other words, fill the sea with a suitable ground level. Moreover, a submerged dike etc. may be provided according to a seabed gradient, a tidal current, etc., and there is no limitation in particular. Depending on the surrounding terrain where the artificial tidal flat is constructed, the earth and sand loading process for embankment may be started from the shore or from the sea. When starting construction from the shore, first place earth and sand on the land, then spread to the sea with a bulldozer, etc., and when starting construction from the sea, the earth and sand are distributed with a pump or a sandboat. In addition, when the artificial tidal flat 2 is distributed after the artificial tidal flat 2 is first introduced and then the artificial tidal flat forming material 1 is distributed, the artificial tidal flat forming material 1 and the underlying viscous soil may be mixed, or surface slippage may occur. Therefore, it is preferable to adjust the amount of sand to be distributed based on an experiment or a similar example of a nearby construction to obtain an optimum sand layer thickness. At this time, if necessary, a net may be laid on the upper surface of the clay soil layer, and there is no particular limitation.

  Hereinafter, the irrigation sand will be described in more detail. Brine is groundwater that contains a lot of salt produced from the groundwater layer. Brine is produced in various places in Japan. For example, water-soluble natural gas deposits on the Boso Peninsula in Chiba Prefecture produce brine rich in iodine. The water-soluble natural gas deposit spread in Chiba Prefecture is a stratum formed about 2 million years ago to 12 million years ago, and natural gas such as methane is dissolved therein. And this water-soluble natural gas deposit contains brine with high salt content along with natural gas. The brine produced from the natural gas deposits in Chiba Prefecture contains a large amount of iodine, and the iodine concentration is about 100 ppm (about 2000 times that of seawater). And about 40% of the world's iodine is produced in this region. In addition, in Niigata and Miyazaki prefectures, brines with high iodine concentration are produced from the underground. The groundwater layer containing brine is thought to have been formed by the accumulation of seaweed and other organic matter containing a large amount of iodine on the ancient seabed. The irrigation sand can be obtained by, for example, precipitating with waste materials when iodine is taken out from the irrigation water.

  In addition, irrigation sand, like river sand, has all the brittle parts that have fallen due to erosion over many years, so sand with high physical wear is suitable for the living environment of benthic organisms. High strength. In addition, since it is exposed to water having almost the same chemical composition as seawater, it also has a feature of containing salt.

Example 1
Below, the result of the submerged sand experiment of the clam using the brackish sand contained in the artificial tidal flat construction material 1 according to the present invention will be described. The test method is to spread the sand sample in a net cage (vertical length of about 25 cm x width of about 40 cm x depth of about 8 cm), bury the net cage in the tidal flat, and then put 15 clams in each sample sand. It is left for a day, and the presence or absence of clams in the clams and the number of submarine individuals are measured. The experiment was conducted on three types of sand, two types of brackish sand and comparative local sand. The two types of brine sand are brine sand A that has settled in the brine pit and brine sand B that has settled in the waste brine pit. The irrigation pit is a pit that stores irrigation sand that is not necessary for the extraction process of iodine from the pumped irrigation water. This is a pit that collects brackish sand. That is, the waste brine is the brine after the water once stored in the brine pit is drained through various facilities. Since the heavy sand settles at an early stage before the brine is drained as waste brine, only light sand remains in the waste brine. Therefore, the brine sand B has a smaller particle size than the brine sand A.

  The results of this experiment are shown in Table 1.

  As shown in Table 1, all the 15 sands in the local sand are submerged, and the submarine sand rate (ratio of the number of individuals submerged in the total number of individuals) is 100%, whereas brine sand A is the submarine sand rate. 87%, brackish sand B has a submarine rate of 93%. Usually, it takes time for clams to dive into the sand brought in from outside. However, according to the artificial tidal flat construction material 1 according to the present invention, as shown in Table 1, it shows a high subsidence rate despite being left alone for one day, and any sand is suitable as a habitat for clams. It can be seen that it is.

  Table 2 shows the measurement data of the particle size distribution of the brackish sand contained in the artificial tidal flat construction material 1 according to the present invention. In Table 2, in addition to the measurement data of the particle size distributions of the brine sand A and the brine sand B, the particle size distribution measurement data of the mountain sand and the above-mentioned local sand are also shown for comparison.

  It is said that the sand particle size suitable for the clam growing environment is empirically and generally 0.1 to 0.2 mm. As shown in Table 2, mountain sand is 95% or more of sand having a particle size of 2000 μm or more, and the particle size distribution rate of 0.1 to 0.2 mm is only about 1%. Not suitable for the environment. Also, the local sand is more than 40% of sand with a particle size of 1000 μm or more, and the particle size distribution rate of 0.1 to 0.2 mm is only about 15%, so it is suitable for the living environment of benthic organisms and clams. I can't say there is.

  On the other hand, as shown in Table 2, the brine sand A contains 25.9% sand having a particle size of 63 to 125 μm and 47.5% sand having a particle size of 125 to 250 μm. The brackish sand B contains 44.1% sand having a particle size of 63 to 125 μm and 43.2% sand having a particle size of 125 to 250 μm. In other words, the particle size distribution rate of 0.1-0.2 mm sand in brackish sand is about 70% -80%, which is very suitable for the living environment of benthic organisms and clams.

  As shown by the above experimental results and the measurement data of the particle size distribution, brine sand is suitable for the habitat environment of benthic organisms, and can increase biological activity. Therefore, the water quality is purified by benthic organisms, and the coastal environment can be restored.

[Soil improvement material]
By the way, the present inventors propose a soil layer improving material, a crop-cultivated soil, a crop-cultivated soil creation method, and a crop-produced method that can promote the cultivation of crops in place of sea sand.

  The field (agricultural crop cultivation soil) according to the present invention is created using a soil layer improving material mixed with brine sand produced from a groundwater layer. In the present invention, irrigation sand produced from a groundwater layer is used in field creation. In addition, the crop cultivation soil which concerns on this invention may be used in the state put into the pot plant etc. besides the form as a field, and is not specifically limited.

  In the present embodiment, ground material for improving the soil layer used for field development may contain crushed shells such as scallops and oysters. Moreover, a fertilizer may be mixed with this and it does not specifically limit.

  By the way, it is known that the growth of crops is improved by using sea sand as a guest soil when cultivating crops that require countermeasures against continuous cropping and those that require air permeability and drainage. However, as mentioned above, it is currently difficult to obtain sea sand.

  Therefore, in the crop production method according to the present invention, irrigated sand is used as a soil for cultivation of crops. When irrigation sand is used as guest soil, the irrigation sand is transported to the field and then manually put into the soil. Then, after soiling, soil disinfection and fertilization are performed, and crops are cultivated by performing preventive spreading and topdressing according to the crops to be cultivated. The crop production method using irrigated sand as a suitable soil is suitable for the cultivation of gold carrots, gold carp, figs, radish, lettuce and the like.

  In addition to mixing irrigation sand into the existing field soil as a guest soil to create crop cultivation soil, the soil layer of the existing paddy field is removed and the soil layer improving material according to the present invention is newly put into the soil. By using it, a new crop-cultivated soil may be created, and further, it may be constructed by spreading other gravel under the lower layer, and is not particularly limited.

  As described above, the feature of brackish sand is that it is exposed to water having almost the same chemical composition as seawater, so that the composition is close to that of sea sand. Therefore, the cultivation of crops can be promoted by using brine sand having a composition similar to that of sea sand as the soil of the field (that is, as soil layer improving material). In addition, brackish sand often contains iodine and various minerals, is rich in nutrients, and can further promote the cultivation of crops. Therefore, according to the soil layer improving material according to the present invention, the soil quality deteriorated due to continuous cropping or the like can be made into coarse soil with good air permeability and drainage and fertile soil, and the environment can be restored. Can do.

(Example 2)
Below, the result of the growth experiment of Kinki ginseng using brackish sand will be described. Kinki ginseng is cultivated in sand and needs to be replenished with sea sand regularly to maintain productivity. Kagawa Prefecture is a typical production area for Kintoki ginseng, but as mentioned above, it is currently prohibited to collect sea sand in the Seto Inland Sea. For this reason, a substitute material for sea sand is demanded, and fine sand for concrete aggregate is recommended in Kagawa Prefecture. However, the fine sand for concrete aggregates does not necessarily maintain the productivity equivalent to that of sea sand, and therefore other sea sand substitute materials are required. Therefore, in order to demonstrate the effectiveness of applying irrigation sand in the cultivation of agricultural crops, we conducted a growth experiment of Kinki Ginseng using irrigation sand.

  Here, the method of this experiment will be described. In this experiment, hairy seeds of “Honbenikitokininjin” were used. First, the seeds subjected to hair removal treatment were immersed in a belanate 500-fold diluted solution for 30 minutes to disinfect the seeds. Next, the seeds were soaked with water all day and night, and then sown in a plastic pot for research (a Wagner pot having a top surface of 1/2000 are = 0.05 square meters).

  Experiments include sea sand, fine sand for concrete aggregate, brackish sand, and sand mixed with brackish sand and concrete aggregate fine sand in a ratio of 2: 1 (hereinafter referred to as 2: 1 mixed sand), A total of five types of sand, which is a mixture of brine sand and concrete aggregate fine sand in a ratio of 1: 2 (hereinafter referred to as 1: 2 mixed sand), was performed. As these fertilizers, 5 g of rapeseed meal, 5 g of humic acid bitter fertilizer, 5 g of bitumen lime, and 0.5 g of material for molten traces were applied to these sands as a fertilizer. In the experiment, 8 pots were prepared for each type of sand.

  In each pot, a groove having a depth of about 2 mm passing through the center of the pot was formed on the upper surface of the sand, 75 seeds were sown at equal intervals in this groove, and sand was applied, followed by sufficient watering. In this experiment, at the time of sowing seeds, the pot was placed in an open field field and cultivation management was performed. In winter, however, the pot was placed in a glass greenhouse set at a minimum night temperature of 10 ° C in order to reduce the effects of low temperatures. Brought in and cultivated. In addition, after the emergence was stabilized, thinning was performed in stages, and finally, each pot was thinned so that there were 5 strains. In addition, irrigation was performed by irrigating about 1 liter of each pot once every two days while observing the degree of soil drying. The fertilizer was applied as shown in Table 3 with reference to conventional methods. In addition, other cultivation management such as pest control was also carried out in the conventional manner.

  In addition, a growth survey was conducted once every two weeks, and a harvest survey was performed by measuring root length and root weight. In the harvest survey, in order to exclude extremely large and small ones, for each type of sand, arrange all the individuals in order from the one with the largest radish, remove 5 individuals in order from the largest one, and remove the remaining individuals. Of these, 20 individuals from the largest were used for the survey.

  Below, the result of the growth experiment of Kinki ginseng is demonstrated in detail using FIGS. FIG. 2 is a diagram showing the germination situation of Kinki ginseng. FIG. 2 shows the germination situation 15 days after sowing. Moreover, FIG. 3 is a graph which shows transition of the germination rate of the carrot carrot. As shown in FIGS. 2 and 3, germination is delayed in sand mixed with brine sand, and germination rates up to 27 days after sowing are 78% for sea sand, 79% for fine concrete sand, and 1: 2 mixed sand. 76% for 2: 1 mixed sand and 41% for brackish sand.

  From this experimental result, the germination of Kintoki ginseng was remarkably slowed in sand mixed with 2/3 or more of brackish sand. This is presumed that the salt concentration is contained in the irrigated sand, and that the increase in the salt concentration accompanying the increase in the mixing ratio of the irrigated sand was manifested as a salt disorder in the germination of the Kintoki ginseng. From this, it is thought that it is necessary to avoid mixing irrigation sand over 1/3 of the soil during sowing.

  Furthermore, the plant height and the number of leaves were investigated as indicators of subsequent growth of Kinjin carrot. Table 4 is a table | surface which shows transition of the plant height of Kinki ginseng. Table 5 is a table showing the transition of the number of leaves of gold carrot.

  As shown in Table 4, the plant height of Kinki ginseng becomes significantly larger with 1: 2 mixed sand after 51 days of sowing, then 2: 1 mixed sand, sea sand, and concrete sand, followed by brine sand. Became the smallest. This trend became clear from around 65 days to around 92 days later. After that, from about 92 days later, the growth of Kinki Ginseng in irrigated sand became good. In addition, from around 133 days, the growth of gold carrots in the 2: 1 mixed sand improved, and was almost the same level as the 1: 2 mixed sand. On the other hand, the height of sea sand and concrete fine sand not mixed with brackish sand decreased.

  Moreover, as shown in Table 5, although the difference with the kind of sand was small about the number of leaves, the tendency similar to a plant height was shown. That is, the number of leaves was highest in the 1: 2 mixed sand, then in the 2: 1 mixed sand, and in the brine sand, sea sand, and concrete fine sand, the number of leaves was small.

  From the results of this growth survey, it was found that the growth of concrete sand, which is an alternative material for sea sand, has a tendency similar to that of conventional knowledge that it is inferior to sea sand. And compared with the growth in the sea sand and the concrete fine sand, the growth in the 1: 2 mixed sand is significantly superior in the first half of the cultivation, and the vigorous growth is also seen in the 2: 1 mixed sand from the second half of the cultivation. It was. From this, it is possible to promote the growth of Kinki ginseng by mixing the irrigated sand, and it is effective to add about 1/3 in the first half of the growth and about 2/3 in the second half of the growth. it is conceivable that.

  In addition, as described above, it is considered that the initial growth was inferior when the mixing ratio of irrigated sand was large, because of salt damage, but compared with sea sand and concrete fine sand, Since the initial growth was promoted in the 1: 2 mixed sand mixed with 3 and the growth of the above-ground part was promoted most in the 2: 1 mixed sand mixed with 2/3 brine water in the latter half of the experiment. The brackish sand is considered to have an effective component or condition that promotes the growth of the above-ground part of Kinki Ginseng.

  Finally, we conducted a survey on the harvest of Kinki Ginseng. FIG. 4 is a diagram showing a state of gold carrot at harvest time. FIG. 4 shows an average size of carrot carrot for each sand used for cultivation. As shown in FIG. 4, Kinki ginseng cultivated using 1: 2 mixed sand and 2: 1 mixed sand, as well as the survey results of plant height and the number of leaves, use brine sand, concrete fine sand and sea sand. Compared to the cultivated gold ginseng, it shows good growth.

  Table 6 is a table showing the fresh weight, the diameter of the enlarged radish, the length of the enlarged radish, and the sugar content of the enlarged radish at the time of harvest.

  As shown in Table 6, the fresh weight of Kinki Ginseng above the ground becomes the heaviest with 2: 1 mixed sand, which was the largest in plant height, followed by 1: 2 mixed sand and brine sand, followed by fine concrete sand and sea sand. Then it became very light. This tendency was also observed in the fresh weight of beetroot. That is, it was heavier with 1: 2 mixed sand and 2: 1 mixed sand, and significantly lighter with brine sand, concrete fine sand, and sea sand.

  In addition, Kinoki ginseng cultivated in 1: 2 mixed sand and 2: 1 mixed sand has a fresh weight of the above-ground part and fresh weight of radish, as well as fertilizer. There was also a tendency for the radish diameter and the enlarged radish length to increase.

  On the other hand, the sugar content of daikon radish is the highest in Kinki Ginseng cultivated with 2: 1 mixed sand, and then also shows high value in Kinki Ginseng cultivated in brine sand, The sugar content of Kinki Ginseng cultivated with sea sand was slightly lower than those, and the 1: 2 mixed sand had the lowest sugar content.

  From the results of this harvest survey, it can be seen that the growth of the above-ground part also affects the size and weight of the radish at the time of harvest. In other words, the enlarged root diameter, the enlarged root length, and the fresh weight of the enlarged radish of the gold carrot cultivated with the 2: 1 mixed sand and the 1: 2 mixed sand in which the growth amount of the above-ground part (the number of leaves and the plant height) has increased. Since the value was larger than that of Kinki Ginseng cultivated with other sand, it became clear that the yield increased by using brackish sand.

  Furthermore, the 2: 1 mixed sand has the highest sugar content of the daikon roots at the time of harvest, and even when cultivated with only the brackish sand, the sugar content was high. It is considered that the sugar content of Kinoki ginseng can be increased by the effects of the active ingredients contained in the stress and brackish sand.

  In addition, although the carrot carrot sugar content of gold carrot of 1: 2 mixed sand showed the lowest value, the initial growth of the above-ground part was remarkably good in 1: 2 mixed sand, and therefore it had flowered. It may be the cause. In other words, it is thought that the nutrients were deprived by the petal development, and the sugar content of the radish decreased accordingly. Therefore, when a flower bud is formed, it is considered that the sugar content can be increased by picking it.

  From the above, when citrus sand is used in cultivation of gold carrot, growth of the above-ground part can be promoted to increase the yield, and the sugar content of the radish can be increased. In particular, the use of brackish sand mixed with fine concrete sand makes it possible to produce extremely superior cultivation results compared to the case of using only fine concrete sand and compared to the case of using only sea sand. Is obtained. In addition to gold carrots, brackish sand, for example, radish, lettuce, spinach, Japanese mustard spinach, Chinese cabbage, onion, green onion, winter rice cake, pepper, sweet potato, spring chrysanthemum, burdock, sweet potato, ginger, peanut, fig, etc. It may be used for cultivation of other crops. Moreover, you may adjust the ratio of brackish sand according to cultivation time.

  Thus, according to the soil layer improving material, the crop cultivation soil, the crop cultivation soil creation method, and the crop production method according to the present invention, the ginseng carrot can be used without using sea sand that has become difficult to obtain for environmental conservation. It is possible to promote the cultivation of agricultural products such as irrigation sand and to make effective use of brine sand.

  In the present embodiment, specific examples have been described. However, the above-described examples are illustrative, and the present invention is not limited to the above-described examples, and is described in the claims. Various changes can be made within a range.

  The environmental improvement material according to the present invention can be used as an environmental restoration material in coastal areas, and is particularly suitable for the creation of an artificial tidal flat in an environment suitable for growth of benthic organisms such as bivalves. Moreover, the environment improvement material which concerns on this invention can be utilized also for improvement of the environment etc. of the cultivated land which grows agricultural products as a soil layer improvement material.

It is a figure which shows the artificial tidal flat which concerns on this invention. It is a figure which shows the germination condition of the gold carrot in the growth experiment of the gold carrot using irrigation sand. It is a graph which shows transition of the germination rate of Kintoki ginseng in the growth experiment of Kintoki ginseng using irrigation sand. It is a figure which shows the mode of the gold carrot at the time of the harvest in the growth experiment of the gold carrot using irrigation sand.

Explanation of symbols

1 Artificial Tidal Flat Construction Material 2 Artificial Tidal Flat

Claims (8)

  An environmental improvement material characterized by containing irrigation sand contained in irrigation water produced from a groundwater layer.   The environmental restoration material in the coastal area which consists of the environmental improvement material of Claim 1.   An artificial tidal flat characterized in that it is constructed using the environmental restoration material in the coastal area according to claim 2.   An artificial tidal flat construction method comprising constructing an artificial tidal flat using the environmental restoration material in the coastal area according to claim 2.   A soil layer improving material comprising the environment improving material according to claim 1.   A crop-cultivated soil comprising the soil layer improving material according to claim 5.   A soil cultivation method for crop cultivation, comprising mixing the soil layer improving material according to claim 5.   A method for producing crops, comprising using the soil layer improving material according to claim 5 as a soil for cultivation of crops.